Lehs-compaeator



A. B. WELLS.

LENS common. APPLICATION F|LED SEPT- 15, I916.

1,307,528. Patentd June 24, 1919.

2 SHEETSSHEET I.

lullr 'HIIIHIIIIIIIIHHHHHHHIHI mmlron V ALBERT B. WELLS +h+wr u mw ATTORNEYS A B; WELLS LENS COMPARATOR. APPLICATION FILEDSEPT.15. 1916.

Patented 111E2 1, 1919.-

2'SHEETSSHEET 2. j

7 INVENTOR AL BERT BHWELLS A TTORNEKS WELLS, OF SOUTI-IBBIDGE, MASSACHUSETTS.

mns-coivrrnnn'rca menses.

To all whom it may concern:

Be it known that I, ALBERT B, WELLS, a citizen of the United States, residing at Southbridge, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Lens- Comparators, of which the following is a specification.

This invention relates to an improved device to be knownas a lens comparator, which shall be particularly valuable in determining the relative properties and especially the heat absorbing or protecting value of varyinc forms of lenses. 7

ne of the leading objects of the present invention is the provision of a compact and efficient device which may be readily transported if desired, and which will serve to accurately and readily determine the heat or infra red ray transmission of various substances, although particularly adapted for use in connection with ophthalmic or eye protectin lenses.

A furt er object ofthe present invention is the provision of an improved device requiring a minimum of heat but which will utilize the small amount of heat generated to advantag to the end that eficient and accurite reading'may be accomplished therewit 1 Other objects and advantages of my im proved device should be read y apparent by reference to the following specification taken in connection with the accompanying draw; ings forming a part thereof, and it will be understood that I may make any modifications in the specific details of construction shown and described within the scope of the appended claims without departing from or exceedir the spirit of the invention.

Figure I represents a side elevation of one embodiment of my invention.

Fig. II represents a longitudinal vertical sectional view thereof.

Fig. III represents a horizontal longitudinal sectional view.

Fig. IV represents a side elevation of a modified construction.

Fig. V represents a longitudinal sectional view of the structure illustrated in Fig. IV.

Fig. VI represents a. perspective view of a collapsible structure. I

Fig. VII represents a side elevation of the structure shown iii-Fig. VI in folded or collapsed position.

Specification of Letters Patent. Patented Jung 2%, 1919, Application filed September 15,1916. Serial No. 120,412.

On Sheet -1 of the drawings, where I have illustrated one embodiment of my invention, the numeral 1 designates the base of my device having rising therefrom adjacent one end the casing 2, within which is provided the thermally insulated chamber 3, this chamber being shown in the present instance as formed bya cylindrical wall of suitable material to reflect the heat radiations within the chamber, for purposes of illustration a glass wall 4: being shown suitably coated on its inner surface with a film 5 of material which will reflect heat radiations, a small portion of the wall 4: being shown left blank as at 6 to permit radiations to enter the chamber at this point, a corresponding aperture or passage 7' being formed through the casing 2.

It will be particularly noted that on account of the cylindrical form of the chamber any heat radiations entering through the aperture 7 and space 6, if focused substantially at the center of the casing, to a large extent will be re-focused back again to the center of the device, while it is, of course, at once apparent that practically none of the radiations can pass outward through the film so that the entire efi'ect of the said heat radiations within the chamber may be observed.

For the purpose of observing the eflect of these radiations I preferably provide a removable cover member 8, having the supplemental cover portion 9 of thermally insulating material to serve as a closure for the chamber proper, said cover bearing centrally thereof a thermometer or other heat actuated indicator 10. In the drawings I have shown a thermometer 10 having its bulb 11 provided with a coating 12 of'suitable heat ablight bulb 13, and place on-the base adjacent the bulb 13, the reflector member 14, the relative positions of the bulb and reflector and the curvature of the reflector being such I that radiations from the bulb toward the reflector will be focused back past the bulb 13 through the aperture 7 and substantially I we onto the bulb 11 of the thermometer 10, the bulb preferably being adjustably mounted to facilitate proper focusing.

It will thus be seen that upon energization of the bulb 13 or other source of heat radiations located at this point, if the aperture-7 their value in protectin the eye from heat and for comparing di erent lenses of the same k1nd, or lenses of different kinds as regards their heat transmission.

To accomplish this result I secure on the caslng 2 about the aperture 7 the holder or. holders 15 adapted to receive one or more lenses 16, the lenses thus being interposed in the path of the heat radiations and serving to shut off a greater or less amount'of said radlatlons according to the heat transmission of the particular lens employed.

In connection with thepresent application it is to be understood that there are, broadly speaking, two general classes of heat transmission, the one being conduction, and the second radlatlon primarily by bodies heated to luminosity, the latter being the more dangerous and objectionable since radiations are much more powerful in their action at a distance from the source of heat than is the heat of conduction, but on the otherhand be ng more readily controlled on account of be ng capable of reflection by polished surfaces without being absorbed to an appreciable extent by those surfaces. It is this radiant heat with which I am particularly concerned in connection with the present case. In Figs. IV to VII inclusive of the drawings I have shown an apparatus slightly modified from that just described, in that in place of employing an entirely, inclosed chamber I make use of the funnel shaped member 17, which may be of glass, metal or other material, which has a reflecting inner surface 18, thus thermally insulating the outer portion of the member 17 from heat radiations entering Within the interior of chamber portion of the device.

As will be most clearly understood by reference to V, there is suitably mounted within the chamber thus formed the thermal indicator 10 secured as by the cap 19, to the indicator, and screwing over the smaller end of the funnel or chamber member, while the other end of the chamber member. 17 has the flared portion 20, againstwhich the lens-or other material 16' being tested may be placed, the operation of the device being as has just been described. I

Referring especially, however, to Figs. VI

' and VII, it will be noted that in this form of my construction I have shown a particuthe larly desirable portable device comprising Y the blocks 21 and 22 at opposite ends of the construction, each provided with a pair of guide bars23 slidably enga ed in the depending flanges 24 of the p atform 25 on which is mounted the pedestal 26 bearing the bulb 1 3. It is to be noted that this pedestal is illustrated as cylindrical in form and is adapted to serve as a reel to contain the electric cable 27, having on. its outer end the plug 28 to permit coupling the device to an ordinary light socket. Also rising from the platform 25 is a hollow cylindrical carrier 29 adapted to receive the thermal indicator 10 when it is removed from the device.

In use the platform 21 is pulled out the full extent of its guides 23 which have interlocking engagement with the flange 24.- to limit their outward movement, while the thermal'indicator 10 is laced in position at the small or reduced en' of the member 17 as illustrated in Fig. 'V. The latform 22 is likewise moved a distance rom the platform 25 and thus the source of luminosity or heat radiations 13, and the members 21, 22 and 25 are suitably relatively shifted as desired, to properly focus the heat radiations from the source of illumination 13 onto the reflector 14: and thence onto the member 17 and onto the bulb portion of the thermometer or indicating device 10, as is indicated by the dotted lines in Fig. V.

Onthe other hand, when it is desired to carry the device, it is merely necessary-to loosen the plug and allow the electric cable to be coiled within the receptacle 26 and to press the members 21 and 22inward toward platform, when the parts will assume their folded position, as indicated in Fig. VII,'the thermometer being plated in its protecting casing 29 and the parts occupy ing the compact readily carried form shown in VII. 1

I claim: a

1. A device for the urpose described, comprising a thermally lnsulated chamber,

an indicator within the chamberhaving aheat absorbing portion, the chamber havmg an opening at one side thereof, means for producing heat radiations, means for focusing the heat radiations through the opening in the chamber onto the heat absorbing ortion of the indicator, and a holder adacent the opening adapted to support a device to be tested in the path of the entering heat radiations to eliminate a portion thereof.

2. A device for the purpose described,

comprising a thermally.i-n sulated chamber, an indicator within the chamber having a heat absorbing portion, the chamber having an openingfat one side thereof, means for producing heat radiations, means for focus ing the heat radiations through the opening in the chamber onto the heat absorbing pormemes Q tion of the indicator, means for increasing the apparent heating efliciency of the ther- 11ml units introduced into the chamber; and a holder adjacent the opening adapted to support a device to be tested in the path of the entering heat radiations to eliminate a portion thereof.

In testimony whereof I afiix my signature in the presence of tWo Witnesses.

ALBERT B. WELLS.

Witnesses:

H. K. PARsoNs, E. M. HALvoRsEN. 

